grub-install problem

[Tom H]

On Sat, Mar 9, 2019 at 1:02 AM Bob <ubuntu-qygzanxc at listemail.net> wrote:
> ** Reply to message from Tom H <tomh0665 at gmail.com> on Sat, 9 Mar 2019 00:21:38
> +0100
>> On Fri, Mar 8, 2019 at 11:57 PM Bob <ubuntu-qygzanxc at listemail.net> wrote:


>>> I have two partitions with Ubuntu installed on my computer. SDA3 is
>>> my normal system, SAD7 is a test system. Whenever I update the test
>>> partition if grub is also updated I need to run "grub-install
>>> --force" on my normal system, SDA3, to get it to be the defaupt boot
>>> partition.
>>>
>>> Today after updating SDA7 it updated grub so SDA7 was the default
>>> boot partition. I booted SDA3 and ran "grub-install --force" which
>>> did not work see the following.
>>>
>>> robert at MARS:~$ grub-install --force
>>> Installing for x86_64-efi platform.
>>> grub-install: warning: disk does not exist, so falling back to partition device
>>> /dev/sda1.
>>> grub-install: warning: disk does not exist, so falling back to partition device
>>> /dev/sda1.
>>> grub-install: warning: disk does not exist, so falling back to partition device
>>> /dev/sda1.
>>> grub-install: error: disk `hostdisk//dev/sda1' not found.
>>> robert at MARS:~$
>>>
>>> I then tried just "grub-install" which normally does nothing because
>>> grub is at the latest level and got the same error messages. I do
>>> not understand why grub is checking SDA1 because it is the EFI
>>> partition. The bios_grub partition is SDA2.
>>
>> 1) You're running "grub-install" as non-root
>
> How stupid of me to forget something that basic.

It's no big deal; a forgotten sudo...


>> 2) Don't use "--force"
>
> In the past I had to use --force because it would not rewrite grub without it.

Try without it first. With i386-pc, it allows you to install grub to a
partition. On x86_64-efi, who knows what it does. Maybe nothing; maybe
it force writes nvram variables.